1. Field of the Invention
The present invention relates to a nitride read only memory (NBit) technology, and more particularly, to methods of forming an NBit and word lines thereof.
2. Description of Related Art
An NBit is a memory which stores data through charge trapping. A typical NBit unit may have two separate charge bits, and thus each unit has doubled memory density. In addition, to satisfy requirements for applying the NBit in the next generation, a dimension of a conventional NBit is required to be decreased continuously. Thus, a liner is further developed nowadays to be deposited on a surface of a hard mask, such that a space between two devices is reduced.
However, in a sub-micron generation (e.g. a 0.1 μm or a 0.075 μm), the above-identified method for reducing the space between the devices results in an increase in a bridge failure rate between word lines.